RHODOCHROSITE & FLUORITE ON QUARTZ

ABOUT THE SPECIMEN

This lovely, artistic, cabinet-sized piece consists of flattened rhombs of pastel-pink rhodochrosite, flanked by glassy cubes of purple fluorite, all strewn atop a blanket of clear quartz points. It's a pleasure to see all of these constituent minerals together, and this makes for an excellent representation of this classic Wutong paragenesis. Many of the rhodochrosite crystals have a light dusting of pyrite along their edges that adds a light glitter under lighting. The fluorite's gemminess allows the viewer to see the rhodochrosite and quartz upon which they grew right through it, and they're also UV reactive, fluorescing a deep blue.

MORE INFO

Discovered in 1958 as a modest lead-zinc-silver producer, the Wutong Mine works ladder-type veins in Cambrian cherts and siltstones through three distinct fault-and-deposition episodes; rhodochrosite arrived in the final stage alongside fluorite and base metals, with fluid inclusion data recording temperatures that cycled from below 200°C up past 300°C before cooling. Manganese-bearing hydrothermal fluids precipitated rhodochrosite as flat rhombohedral discs and stacked parallel crystals - Chinese miners nicknamed certain growth forms "lobster tails" - on gangue of pale green to violet fluorite and pyrite. Geochemical work published in the Mineralogical Record (Lees et al., 2011) distinguished Wutong's relatively simple single-pulse magmatic fluid system from the more complex multi-stage evolution at Sweet Home, despite broadly comparable mineralogy. A 2010 pocket produced the "Emperor of China," the largest known crystallized rhodochrosite specimen at 40×60 cm and 63.5 kg. The mine went into care-and-maintenance status in 2011 with the lower levels subsequently flooded, ending production entirely; all material now in circulation is old-stock, and the finest pieces from the 2009–2010 finds have largely been absorbed into major collections.